Abstract : The report describes the operational results of Ground-Based Propane Cold Fog Dispersal System at Orly Airport, Paris, France during seven periods of cold fog which occurred during the winter of 1970-71. The propagation of RVR improvement and the effectiveness of the fog dispersal operation is described for each case. A cost/benefit analysis demonstrates that the propane fog-dispersal installation at Orly Airport benefits and airlines, airport, and passengers. (Author)